The PSU is the most underweighted component in most builds — and the only one whose failure can take the rest of the system with it. The Mars Score weights wattage headroom, efficiency rating, modularity, ATX 3.0/3.1 support, and warranty.

Wattage sizing: 1.5× to 2× peak load

A modern RTX 4090 / 5090 + Core i9 / Ryzen 9 system pulls 600–750 W under simultaneous CPU+GPU load. Run a 1,000–1,200 W unit to keep the PSU in its high-efficiency band and to cover transient spikes. The Corsair RM1200x SHIFT and Seasonic PRIME TX-1300 are typical of this class.

Efficiency: 80+ Gold is enough; Titanium is luxury

80+ Gold (87–90% efficiency at 50% load) is the mainstream sweet spot. Titanium (94%+) saves a few watts but takes years to repay the premium in residential electricity. Pay for Titanium if you run the PC 24/7.

ATX 3.0 / ATX 3.1 and the 12V-2x6 connector

ATX 3.0 added the 12VHPWR connector for high-power GPUs; ATX 3.1 fixed the connector to 12V-2x6 with better mechanical retention. Buy ATX 3.1 (or use a high-quality cable adapter) for any 4090/5090-class card to reduce melted-connector risk.

Full vs semi vs non-modular

Fully modular cabling (RM1200x SHIFT, PRIME TX-1300 Noctua) is now the default at $150+. Semi-modular keeps the ATX 24-pin and CPU EPS hard-wired but saves money. Non-modular is fine for compact budget builds but messy in larger cases.

Form factor: ATX, SFX, SFX-L

Standard ATX for tower builds. SFX and SFX-L (Corsair SF1000L) for ITX cases — pay attention to clearance with bulky aftermarket GPUs.

Warranty as a quality proxy

10–12 year warranties (Seasonic PRIME, Corsair RM) signal high-tier internal components. Sub-5-year warranties on no-name brands signal the opposite. Never buy a PSU based on price alone.

How vsMars scores power supplies

Each score combines wattage, efficiency rating, modularity, ATX 3.x support, and warranty length per the methodology. Cross-reference with graphics cards for matched wattage targets and gaming PCs for full-system context.

Reader questions

Frequently asked

How many power supplies are catalogued on vsMars?+

17 power supplies from 8 brands are catalogued in this category, each with a complete spec sheet and a transparent Mars Score.

How are power supplies ranked?+

Each power supplie is scored by the category-specific Mars Score formula — a weighted average of normalized specs with the weights published on the methodology page. No editorial hand-tuning.

Which power supplie has the highest Mars Score right now?+

C1500 Platinum leads the power supplies category with a Mars Score of 90.7.

Can I compare two power supplies side by side?+

Yes — pick any two power supplies from the category list and the comparison page renders side-by-side specs, advantages on each side, and a Mars Score verdict.